Resealable closure mechanisms are commonly used on containers that may be used to store perishable contents, such as food. It may be advantageous for such a resealable closure mechanism to form a gastight seal when occluded, because a gastight seal allows the container to be evacuated and vacuum sealed. For example, after the container has been loaded with the perishable contents, a user may evacuate the container of excess gas, for example through an evacuation valve, and vacuum seal the container by occluding the gastight closure mechanism. Perishable contents stored within a vacuum sealed container may remain fresher for a longer period of time than if otherwise stored in the presence of larger amounts of gas, such as air, in an un-vacuumed container. Resealable closure mechanisms have been used to facilitate maintenance of vacuum in containers for an extended period of time.
For example, one such resealable closure mechanism has a first closure element that has first and second interlocking profiles disposed on either side of a first sealing member that is compressible. A second closure element has third and fourth interlocking profiles that interlock with the first and second interlocking profiles, respectively. When the first and second closure elements are occluded, the first sealing member is compressed against the second closure element to create a seal therebetween.
Another resealable closure mechanism has a first closure element with two male interlocking profiles and a second closure element with two female interlocking profiles. At least one of the first and second closure elements also includes high compression members disposed on opposite ends of the closure element or a high compression member disposed between the interlocking profiles. The high compression members are sufficiently long to make contact with the opposing closure element during occlusion of the closure elements before the extremities of the interlocking profiles on either of the first and second closure elements contact the opposite closure element. The high compression members prevent damage or distortion that may be caused to the interlocking profiles during sealing of thermoplastic film to bases of the closure elements.
Further resealable closure mechanisms have opposing first and second closure elements. Each closure element has a sealing member disposed between two interlocking members. The sealing members press against each other to form a seal when the interlocking members are interlocked. In one such closure mechanism, for example, the first closure element has two spaced out-turned male hooks that interlock with two complementary in-turned female hooks disposed on the second closure element. A pressing rib spaced between the out-turned male hooks is wedged into a tapered channel defined by two tightening walls spaced between the in-turned female hooks. Each tightening wall also presses against an inner surface of the adjacent out-turned male hook.
Other resealable closure mechanisms have rounded male and female interlocking profiles. For example, one such closure mechanism has a first closure element with male and female interlocking profiles that respectively interlock with female and male interlocking profiles disposed on a second closure element. Each male profile has a neck and a head and a round zipping groove between the neck and head on each side of the neck. Each female profile has a pair of locking arms, each having a round hooking end. The hooking ends and zipping grooves are congruently rounded such that they form a seal therebetween when each male profile is pressed into the corresponding female profile. In another such closure mechanism, a female profile further includes a central sealing arm disposed between the locking arms. The central sealing arm is sealedly inserted into a coupling groove disposed along a center line of a corresponding male profile when the female profile and the male profile are interlocked.
A flexible reclosable pouch, for example, a thermoplastic pouch, that has a resealable closure mechanism applied across a mouth of the pouch may maintain a gastight seal along a majority of the resealable closure mechanism. However such a resealable closure mechanism applied to the reclosable pouch may suffer from leaks at ends of the closure mechanism where post application crushing and slicing occurs during the pouch manufacture.